Патент USA US3068851код для вставки
Dec. 18, 1962 L. RoBBlNs ETAL HYDRAULIC PRESSURE SYSTEM Filed Jan. 13, 1961 QQ. NN Sm 3,068,841 United States Patent Gtiîce 3,068,841 Patented Dec. 18, 1962 2 1 The invention includes an arrangement in which the 3,068,841 HYDRAULIC PRESSURE SYSTEM Leo Robbins and Jack Bendror, Brooklyn, NX., assign ors to Robbins & Bendror Associates Inc., New York, N .Y. Filed Jan. 13, 1961, Ser. No. 82,503 21 Claims. (Cl. 121-38) This invention relates in general to a hydraulic pres sure system and in particular to a new and useful hy draulic press including an automatic arrangement for rapidly advancing a ram toward a workpiece under low actuating ñuid is sucked into the master cylinder by move ment of the master piston by the pressure of the Huid acting on the hollow slave piston. Thus a small quan tity of ñuid and small pumping capacity is required to maneuver the ram into an operating position while the master piston is actually sucking large quantities of ñuid through a suitable connection through the one end of the master cylinder to the ñuid reservoir. A feature of the invention is that the ram may be operated automatically to advance the ram and upon the ram encountering a major resistance force such as the workpiece to be operated upon, the »tluid pressure is power and low pumping volume requirements and for automatically directed into the master cylinder and eiîecting full force against the workpiece after the ram 15 against the master piston to eiîect the exertion of a large is positioned in contact therewith. compression force by the ram. At the present time, hydraulic presses include, in most A further feature or" the construction is that a low instances, a single cylinder construction for advancing capacity control valve may be employed to effect both the the ram under the force of ñuid to pressurize one side of advancing and the reversing movements of the ram. This a piston connected to the ram. A disadvantage in a sin gle cylinder construction is that a large horsepower re 20 control valve is not required to handle the Íluid which is displaced by the master piston during its movements. quirement for pumping the ñuid to advance the ram is re~ Instead, the valving arrangement includes means to con quired to act against the large area piston, even though the force of the ram is not being applied to a workpiece. nect the master piston to a reservoir upon initiation of return movement of the ram by directing pressurized ñuid The area of the piston must be designed suiliciently large to eiîect a large enough force for effecting sutiicient 25 into the hollow slave piston at a location between the end wall of the master cylinder and the interior wall pressing action on the workpiece, but the ram itself could be advanced by a smuch smaller sized piston area member while it is maneuvered to and from the workpiece. In some instances, hydraulic pressure systems include a of the master piston. The only electrical or manual con trol required is one four-way valve which permits pres surizing of the interior of the slave piston at one side of small sized so-called slave cylinder for the purposes of 30 the master piston end wall and the simultaneous pres surizing of one side of the master piston after the force moving the ram backwardly and forwardly before it con of the workpiece has been encountered, and for alterna tacts the workpiece. Such systems include a control for tively directing the pressure» to the interior of the slave switching to a large size piston for effecting a large force piston on the opposite side of the end wall of the master on the workpiece by the ram.' Such systems have the ob cylinder for the return movement of the ram. The valve vious disadvantage that they require a duplication of the also includes means for connecting the side of the slave hydraulic pressure lines and there is a diñîculty in locating piston which is not pressurized to a reservoir when the the slave cylinderso that the force which it exerts on the other side is pressurized and vice versa. ram will act in a uniform axial direction so that the ram Thus, the invention provides an unusual hydraulic will not be misaligned during its movement. A very important disadvantage of the use of a master piston 40 pressure system for a ram which makes it possible to manipulate the ram by displacing a very small quantity for effecting ram force on the workpiece and the slave of control fluid and by expending a very small amount of piston for advancing the ram is that the control valving horsepower in pumping such tluid. Besides the fact that to switch from the pressurizing of the slave cylinder to it is not necessary to pump a large quantity of iluid inthe the'pressurizing of the master piston must be sutiiciently large to accommodate the displaced fluid from the master 45 manipulation of the master cylinder which exerts the major pressure force on a workpiece, the invention pro cylinder. This, of course, results in a large expenditure vides a system which is much simpler from prior art for valving and associate piping and the requirement for constructions, particularly in respect to the amount of large horsepower motor to operate the pump, since it is parts and conduits required and in respect to the control necessary to handle at least some portion of the liquid of the master cylinder even though a small size slave cylin 50 valves which are necessary. Accordingly, it is an object of this' invention to provide der is operating to maneuver the ram into position. an improved hydraulic pressure system. In accordance with the present invention there is pro A further object of the invention is to provide a hy vided a combination master and slave cylinder construc draulic press including a combination master cylinder and tion which includes a relatively small diameter slave cylin piston construction in which/the slave piston is made der having side walls which are slidable in an end wall hollow and has its walls in «an end wall of the master of the main or master cylinder and which forms at its cylinder for reciprocation therein, and including improved inner end the master piston which reciprocates within the vmeans for manipulating the ram under the control of master cylinder. The center of the master cylinder in the slave piston and for automatically switching to actu cludes a cylindrical portion in which there is drilled a passage for conducting ñuid under pressure to a location 60 ation of the master piston upon contact by the ram of the workpiece or load. ' between the interior face of the master piston and an in A further »object of the invention is to provide an im terior slave cylinder dividing wall formed as an extension proved hydraulic control system for a hydraulic press in of the end Wall of the master cylinder and within the cluding means for rapidly advancing the ram by the dis hollow slave piston. The pressure which is built up within the interior of the hollow pressure slave system 65 placement of a small quantity of control lluid. A further object of the invention is to provide a high causes movement of a ram attached to the end of the piston by the pumping of a relatively small quantity of speed hydraulic press including means for advancing the ñuid which acts against the relatively small area which is exposed within the hollow slave piston and which acts against the end wall of the master cylinder and the interior wall of the master piston to advance the hollow slave ram thereof by the displacement of a small quantity of control ñuid and the expenditure of a relatively small amount of power, and further including automatic means for increasing the pressure force applied on the ram after it contacts a workpiece. piston and the ram. ' 3,068,841 3 4 A further .object Yof the invention is to provide a hy draulic press Which is simple in desi-gn, rugged in con i A combination plunger 'and piston member generally designated 68 lincludes a plunger portion 70 which is slidable in the portion 64 and a piston portion 72 which The various features of novelty which characterize the is slidable within a slightly Vlarger diameter portion 74. invention are pointed out with particularity in the claims 5 The diameter of the piston portion 72 is larger than the annexed to and forming a part of this spe'ciñcation. For plunger diameter '70 for the purpose to be setrfrorth more a better understanding of the invention, its operating fully hereinafter. p advantages and specific objects attained by its use, refer The piston is -biased by means of a spring ‘76 against ence should be had to the accompanying drawing and an end wall 7S which is provided with openings which descriptive matter in which there is illustrated and de lead to passages V80 which connect via a check valve 82 scribed a preferred embodiment of the invention. to the conduit 656' and a passage 84 which connects to In the drawings: a central passage 86 in which a pilot rod memberSS isV FIG. 1 is a top plan view of a hydraulic press con slidable. There is a clearance between »the «piston Jpor- Y structed in accordance with the invention; tion 72 and the cylindrical walls 90 of the 'control valve FIG. 2 is a somewhat schematic transverse horizontal member 54 for the purpose of permitting the passage of section through the combination master and slave cylinder ' pressurized control fluid therearound las will be described and control valve indicated in FIG. l and showing the more fully hereinafter (see FIG. 3). various hydraulic `conduit connections; and The conduit 60 joins to a lflexible conduit 92 which con FIG. 3 is a vertical section taken on the line 3_3 of nects into the hollow slave piston 32 between the exterior FIG. 2 on a somewhat exaggerated scale. end of the cylindrical extension 26 and the end wall 44V Referring to the drawings in particular, the invention thereof. Each of the conduits 92 and 6d leads to a com embodied therein includes ahydraulic press comprising bined conduit 94 which connects to the four-way sole a rigid rectangular frame generally designated 10 which noid actuated valve 62. The conduit 28 also Vconnects includes a front wall 12 against which is rigidly fastened to the four-way solenoid actuated valve 62. a clamping jaw i4 of the hydraulic press. The opposite side of the valve .'62 is connected through A combination master and slave cylinder construction a conduit 96 which leads to a pump 98 which takes suc- Y generally designated 16 is provided with a reinforced end tion in a fluid reservoir 100. A pump motor-V102 is pro vided to rotate the pump ‘98 to pressurize the conduit 96 wall or head 11S which is rigidly fastened to an end wall and the pressure of the ñuid delivered by the pump 20 of the frame 10. ln accordance with the invention, the combination masterV `and slave cylinder and piston 30 through >the conduit 96 Ymay be selectively connected to the conduit 28 or to the conduit 94. Four-way valve 62V member 16 includes a relatively large diameter master cylinder 22 formed as an extension of the head 18 and is also >connected by way of a conduit 104 to a fluid reservoir 106. It should be appreciated that the reser terminating in an opposite end wall or head 24 which is secured to the wall 1S by means of elongated stud or bolt voirs indicated as 5S, 100 and 106 may be and normally members 25. The head 1S includes a central elongated 35 are one and the same reservoir. The operation of the device is as follows: When Vit is cylindrical extension 26 which extends from the head struction and economical to manufacture. . desired `to advance the ram 46 in a direction of the arrow 18 in the direction of end wall 24. The end wall or 108 a lsolenoid plunger 112 is actuated by a suitable elec head 1S and the lcylindrical extension 26 Áare `provided trical control to cause the pressurized `conduit 96 to be withY a passage 2S -for conducting control ñuid through an opening 30 which is located approximately «in the-same 40 communicated to the >conduit 94 and to simultaneously connect .the conduit 28 to the reservoir 106 via the con plane as the Vend Wall 24. duit 104. The construction includes -a combination hollow slave piston and master piston assembly generally designated After the valve Vis :thus positioned„pressure is admitted through conduit 92 to the hollow slave piston 32 at the 32 which includes a cylindrical wall portion 34 which is slidable between suitable seals 36 and 3S in the end Wall 45 location Ybetween the widened end 40 of the cylindrical extension 26 and the end wall 44vto cause a buildup of 24 »and lateral annular extension 40 of the cylindrical pressure therein and movementof the wall `44 away from extension 26, respectively. the extension 26 to displace the ram l46 in the direction of The cylindrical walls 34 define a slave hollow piston the arrow 108. During this time,.conduit 28 is exposed or Ycylinder -member which has one wall closed Vby a master piston 42 in an opposite end closed by a wall 50 through the opening 30 to the interior of the slave piston 32 to a chamber 110 on the opposite side of the widened 44 which is connected to a ram 46. The ram 46 is adapted to be displaced by thehydraulic fluid in direc-V portion 40 of the cylindrical extension 26 and the fluid tions toward and away from the clamping jaws for oper~ pressure is relieved in the chamber 110. This permits the control fluid to lbe bled through the passage 28 to the Y ation on a workpiece positioned Ibetween the-clamping jaws and the ram. In the embodiment shown, the press 55 valve V62 and `conduit 104 to the reservoir 106. _. is a bookbinding press. ' Y. G Thus rapid advanceV of the ram 461is accomplished by means ' The master piston 42 is of a larger diameter than the cylindrical walls 34 and includes a sealing ring-48 to of the displacement of a'small quantity of fluid ¿in a hol low sla-ve piston >32. valve member Agenerally designated 5?, which is providedV chamber 64 of the control valve 54 and through conduit 50 tothe ychamber 52. Thus, a large quantity of liquid `is displaced by the `movement of the master piston 42 but this liquid` does not have Vto be separately pumped It should be appreciated that when the Vram y46 is dis maintain Ya liiuid tight seal during the reciprocation of Vthe piston-42 in the cylinder 22. A conduit 50 ‘is pro 60 placed >by the pressurizing of the slave piston 32 in the chamber formed .between the end 4of the cylindrical ex vided for directing Aiiuid into the space 52 between the tension 26 and the walls44, >the master piston 42 is also Vend wall» 18 and the master pistonV 42. The conduit 50 moved within the cylindrical walls 22. This movement alsojprovides la passage for relieving the pressure during of the master piston 42 causes the sucking in of Yiiuid the‘return movement of the piston 42. ' from the reservoir 58 through the conduit 56 into the A Vfeature of the invention isv the provision of a novel withan opening at one end 56 which is connected to an oil reservoir 5S and a small size opening 60 which is connected to' a four-way solenoid control valve generally designated 62,.Y An intermediate opening 64 is provided and lit does not pass through the control -valve 62. Y Yin,Y the control valve member '54 in alignment with theV YWhen the ram 46 meetsresistance such -as by contact opening 50 in the' end wall 1S. The interior of the valve ing a- workpiece, the pressure in' conduits 92, k94 and 60 builds up toa value suíîicient to Vpush the pilot rod 88 in ' control member 54 Vis provided with a bore portion 64V ' of larger internal'diameter than the conduitV 56 and a ~ the ,control valve 54 to the left asY indicated in FIG. 2.YY 1 beveled portion 66 connecting conduit 56 and portion 64. 75 This causes movement of the plunger/17,0 to the left as "Y 3,068,841 5 6 . viewed in the drawings until the whole plunger and piston assembly 63 moves suliiciently to close the opening 50. At this time pilot rod 88 has moved sufficiently to the left to uncover the passage S4. The pressurized ñuid from the conduit 60 passes through the passage 84 and around the piston 72 to a- space within the valve between the piston 72 and the plunger 7i), while it continues to urge the combination piston and plunger member 68 to the left to close thus preventing any escape of Huid. The plunger portion '7d moves sufficiently to uncover the passage 5@ and permit it to communicate with the passage 68 through the passage 34 to cause the fluid to enter the chamber 52 and displace the master piston 42 to cause the exertion of a large amount of force by the ram 46 on the workpiece. Once the ñuidpressure within the chamber 52 is increased, the plunger 7@ is urged against the beveled portion 66 with an increasing force to tightly close oñ the conduit 56 and prevent leakage 42, it may be of much smaller and less costly construc tion than similar valves in prior art hydraulic systems of this character. The advancing and retracting move ment by the slave hollow piston is very rapid. While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the invention principles, it will be understood that the invention may be embodied otherwise without departing from such principles. What is claimed is: 1. A hydraulic system comprising a supporting frame, a master cylinder having end walls of relatively large diameter and being supported on said frame, a combina tion slave cylinder and master piston member including a hollow cylindrical wall portion of smaller diameter than the internal diameter of said master cylinder slidable in an end wall of said master cylinder, said master cylinder including end wall means dividing the interior` of said slave cylinder portion, a master piston formed at one end of oil to the reservoir 5S. When it is desired to retract the ram 46 the plunger 20 of said slave cylinder of substantially the same diameter as the internal diameter of said master cylinder, and 1312 of the valve 62 is actuated to connect the conduit 28 means to selectively pressurize said slave cylinder on alter to the pressure line 96 and the conduit 94» to the reservoir nate sides of said dividing wall means without pressurizing M6. The pump 98 therefore directs duid through the said master cylinder to cause relative movement of said conduit 28 and out the opening 39 to pressurize the chamber lli). Since the cylindrical extension 26 and its 25 slave cylinder in respect to said end wall means in accord flange portions 46 are stationary, the master piston 42 is ance with the _side thereof which is pressurized. - 2. A hydraulic system for a press and the like compris displaced by the action of the fluid within the smaller annular area defined at one end of the chamber liti. ing a master cylinder of relatively large diameter, said master cylinder having spaced end walls, one of said end Since the conduit 92 and the conduit 61B are connected to the reservoir, the pressure is relieved on the other 30 walls having a central extension extending outwardly side of the cylindrical extension in the slave hollow piston therefrom toward the opposite end wall, a combination 32 and return movement may be accomplished. How master piston and slave cylinder member slidable in an ever, as long as the plunger '743 closes the opening to the end wall of said master cylinder and extending around conduit 56, the oil in the chamber 52 is forced to iiow the extension portion of the opposite end wall, said ex through the chamber within the walls of the cylindrical 35 tension portion including a widened portion substantially valve 54 between the plunger 70 and the piston 72, dividing the interior of said slave cylinder, and pressure around the piston and through the check valve S2 to the conduit means connected directly to said slave cylinder conduit 6i). The clearance between the piston 72 and on each side of said widened portion without communi the cylindrical walls 90 is arranged to offer some resist cating with said master cylinder, whereby said cylinder is ance to the large flow of oil from the chamber 52. Some 40 movable relatively to said end wall of said master cylinder pressure will therefore be maintained in the chamber 52 in accordance with which side of the interior of said which will push back the combination plunger and pis slave cylinder in respect to said widened portion is pres ton rods 68 and to first close and thereafter open the port surized. 64. This occurs because the piston 72 is of a larger di 3. A hydraulic system for a press and the like accord ameter than the plunger 70 and the pressure acting against 45 ing to claim 2, wherein said extension portion of said the face of the piston overcomes the pressure acting one end wall includes an internal conduit for directing against the face of the plunger. The spring 76 aids in fluid to the interior of said slave cylinder on one side of moving the combination plunger and piston member 68 the widened portion which divides said slave cylinder. to the right but it is gradual until the plunger 7 0 uncovers ~4. A hydraulic system for a press according to claim the port 64. After the port 64 is partly opened, the pres 50 2, including a second conduit connected to said master sure in the chamber 52 immediately drops as the conduit cylinder on the opposite side of said master piston from 513 communicates with the conduit S6 and the spring 76 said slave cylinder, means to selectively pressurize the is therefore able to return the combination piston and conduits on alternate sides of said widened portion, and plunger member 68 to the position indicated in FIG. 2. means connected to said pressurizing means and respon Thus, it can be seen that the ram 46 may be moved 55 sive upon the buildup of pressure to a predetermined or manipulated into a position by the displacement of a amount to connect said second conduit to said pressurized small quantity of fluid requiring a pump of much smaller means. ' horsepower than if the master piston 42 had to be dis 5. A hydraulic system for a press according to claim placed by directing fluid against its face during the manipu 2, wherein said means to connect said second conduit to lation stage of the rarn. The invention includes means 60 said pressurizing means includes a control valve, said for automatically causing the pressurizing of the master control valve having an intermediate conduit connected piston 42 when the load is encountered by the ram, caus to said second conduit, reservoir means connecting one ing a raising of the pressure in the conduits which feed end of said control valve, pressurized ñuid means con the slave portion. Since the operation of the device de necting the opposite end of said control valve, said control pends on the pressures within the connecting conduits 65 valve having a displaceable valve member therein movable and the associated portions of the control valve, the equip upon increase of pressure in said pressure conduit means ment requires very little maintenance and very little atten to close said reservoir means from communication with tion in its operation. The device may be operated with said second conduit. a single electrically actuated four-way control valve for 6. In a hydraulic system including a master cylinder effecting forward or reverse movement of the ram 46 as 70 of relatively large diameter having closing head portions desired. The overall construction is very inexpensive to at each end, one of said head portions having a central manufacture and the saving in horsepower requirements opening, a central portion extending interiorly of the other of said head portions to Isaid central opening, including is considerable. Due to the fact that the four-way sole noid control valve only handles a small quantity of liquid a widened outer end, a combination master piston and and not the full quantity of liquid displaced by the piston slave cylinder member slidable on said central portion in 3,068,841 7 8 sealing >engagemnt with the end Ahead of said master cyl inder and the widened outer end of said central portion, 15. A hydraulic system according to claim~»14, includ a ?irst conduit deñned in said central portion and extend ing a second passage formed in said valve wall and con nected to said second conduit and the intermediate cham ing through the connected head and in communication with the interior of said slave cylinder on the interior ber of said valve, said second passage having a check valve therein. side Vof said widened end portion, a second conduit con 16. A control valve for a fluid system comprising `a v valve body having an opening> at one end, a hollow in nected to said slave cylinder on'the opposite side of said widened -end portion, a liquid reservoir, a liquid pressure line, and valve means for selectively connecting said pres terior chamber portion in alignment with said opening, a first connection intermediate the length of said body `to sure line to said iirst conduit and connecting said second 10 said central chamber, a second connection connecting the conduit to said liquid reservoir and for thereafter connect opposite end of said separate chamber, a combination ing said second conduit to said liquid pressure means and plunger and piston member slidable in said chamber andV said first conduit to said liquid reservoir. Y 7. A hydraulic system according to claim 6, wherein said Valve means is a four-way solenoid actuated valve. including a plunger portion, a piston portion and a pilot rod disposed adjacent said piston portion extending to .said second connection, said pilot rod Vbeing displaceable'uponv 8. A hydaulic system according to claim 6, including increase in pressure in »saidf second connection ,to dis means connecting said master cylinder on the opposite place said combination plunger and piston rod member, side of said master piston from said slave cylinder portion said plunger portion being Vof a size to close said open to said liquid reservoir, and valve means in said'connec ing and having a skirt portion movable to open and close tion Vincluding means automatically operable to connect 20 said first connection, said plunger being moved to an ex said master cylinder to said liquid reservoir upon the pres treme vposition to completely close said opening and the surizing of said first conduit. » communication of said ñrst and second connections on 9. A hydraulic system according to claim 8, wherein the interior of said valve. said valve means includes means to'connect said master , ' ~ Y 17. AV control valve for the fluid system according to cylinder to said liquid pressure line upon the building up 25 claim 16, wherein said piston portion is of larger .diam eter than said plunger portion >but is not as large in diam-iV of pressure _within said second conduit to a predetermined amount. Y eter as the bore of the interior walls of said Valve body c 10. A hydraulic system according to claim 9, wherein whereby iiuid may bypass annularly aroundV said piston said valve means includes a third conduit connection to from said íirst connection to said second connection. 18.V A control valve for a lluid system according to claim 17, including a passage defined in said valve body said master cylinder between said master piston and the 30 Y adjacent head, and a plunger displaceable `between a posi tion closing said third conduit and to a position connecting connected between said second connectionand the interiorV said third conduit to said ñuid pressure means. chamber of said valve, said passage having a check valve ' 1l. A hydraulic system according to claim 6, including therein. , a Vthird conduit connected to said master cylinder between 35 19. A control valve for a liuid system according vto said master piston vand the adjacent head and connected claim 18, including a passage deñned between said second to said second conduit, a control valve disposed in said third conduit, said liquid reservoir being connected to connection and central chamber of said valve body. v20. A control Valve for a fluid system according toV said valve means at one end thereof, said `connection to claim 16, wherein said valve body includes ,acentral .pas 40 said îliquid reservoir being in communication with said sage for said pilot rod, a first passage communicating third conduit >through the interior of one end of said with said second connection and said central chamber, 2a valve, said third conduit ,and second conduit being in second passage communicating with said passage lforsaid communication at the opposite end of said valve, and a pilot rod and said central chamber, said pilot rod being plunger member >slidable to close the communication be displaceable toV uncover said Yiirst passage .to Ípermit fluid 45 tween said third condnit and said reservoir in one extreme connection between said second connection and said cen position and in an opposite extreme position to close the tral chamber whereby to displace said plunger ¿to initially communication between said third conduit and second cover said ñrst connection and thereafter to cover `said conduit and to open the communication between said Vthird conduit and said reservoir. V12. VA hydraulic system according to claim 11, wherein 50 21. A control valve for a iluid system according to said plunger means includes a slidable member having l claim 16, wherein the annular clearancebetween said opening. interior walls of said valve. , c Y 14. A hydraulic system according toV claim 13„wherein v ' ‘ valve body isV of an amount to create'suii‘icient resistance connection to said reservoircand having a cylindrical skirt said combination plunger and piston member includes a piston formed at one end having a larger diameter than said plunger member but Ybeing of less diameter than the ' ‘ piston portion of the bore of the interior walls> of saidV Y a plunger at one .end movable against a seat to close said portion simultaneously uncovering ?said third conduit for communication with said second conduit, 13. A hydraulic system according to claim 12, wherein ' to the flow ofV fluid to .cause a back pressure sufficient to 55 force said plunger portion to open the connection be tween the chamber of the master cylinder and the liquid reservoir, said plunger portion being of a smaller eiîec tive area than'said piston portion. 60 kReferences Cited in the ñle of this patent said valveV has walls having a port extending from a lo UNITED STATES PATENTS cation adjacent said >third conduit «connection to a loca-l Hottel ______ __ _______ ___ Jan. 6, 1931 1,788,298 tion intermediate the ends of said Valve, said piston por Ernst ________ ___ _____ __ May ’1, ‘1934 tionlbeing disposed in a chamber Vat the end of said pas 65 ' 1,956,758 2,293,334 Ernst _ _____ __ _____ _____ Aug. 18, 1942 sage, and a pilot rod adjacent said piston portion and 2,437,077 Cole __ ____ ___ ________ __ Mar. 2, V1948 displaceable upon increase in pressure in `said second 2,502,547 Adams et al ____________ __ Apr. 4, V1795() conduit to shift said combination plunger and piston mem '2,636,406 n Salter ____________ ____ __ Apr. 28, 1953 ber to cover the connection to saidreservoir.